Milling cutter



IIIIIIIIIII ER Fmi ` INVUVTOR.

ALBERT' HAGE WM W AffRN Y* Patented Nov. l0, 1953 UNITED STATES :PATENT OFFICE Albert Hage, Toledo, Ohio Application' February 26, 1952, Serial No. 273,377

'I'his invention relates to milling cutters, and an object is to produce a new and improved milling cutter which greatly decreases the cutting or load stress on the teeth when in use; provides increased strength in the weakest region; is so designed that tooth breakage is reduced, thereby substantially prolonging the life of the cutter; and can be economically manufactured and maintained in good working condition at reasonable cost. This application is a continuation-inpart of my co-pending application Serial No. 35,411, filed June 26, 1948, entitled Milling Cutter, and now abandoned.

Another object is to provide a milling cutter having a V-shaped cutting edge capable of producing a square or straight-bottom cut, and yet having a reenforcing web of substantial thickness trailing the cutting edge. To this end, it is intended that the V-shaped cutting edge be equidistant at all points along the V, from the axis of the cutter, and that the outer surface of the reenforcing web be slightly concave behind the cutting edge.

Still another object of the invention is to provide for disposition of the metal peeled off the work by V-shaped, positively raked cutting teeth. lMore particularly, it is now proposed that the base of each cutting tooth be formed with outwardly disposed plow-like surfaces which at the base of the tooth, curve continuously from the surfaces framing the V at the tooth front, and thence merge with the ilat sloping back surface of the next preceding tooth. In addition, the apex of the V is continued forwardly for a short distance, in concave curvature, from the bottom of the tooth front and thence merges into the flat sloping back of the preceding tooth. The curved, outwardly inclined pockets thus formed at the bases of the tooth fronts shed the peeled metal outwardly so that it will not build up between the teeth.

Other objects and advantages of the invention will hereinafter appear, and for purposes of illustration but not of limitation, an embodiment of the invention is shown on the accompanying drawings. in which Figure 1 is a side elevation of a milling cutter;

Figure 2 is a top plan view or edge elevation of the cutter shown in Figure l;

Figure 3 is a perspective view showing the teeth of the cutter shown in Figure 1; and

Figure 4 is an enlarged transverse sectional view on the line 4--4 of Figure 2.

The illustrated embodiment of the invention comprises a rotary milling cutter including a body 1 Claim. (Cl.I 29-103) I0 having a central opening II to fit a rotating spindle to which it may be keyed. 'I'he body III has an annular row of cutting teeth I2, which, in this instance, are integral with the body, the entire structure being a suitable metal produced from a casting or forging or suitable bar stock suitably machined to achieve the desired contour.

Each tooth I2 has a pointed cutting edge I3 from opposite sides of which incline rearwardly straight cutting edges I4 and I5. Cutting edges I4 and I5 are, at all points along their lengths, equidistant from the axis A of the cutter. At the outer side is a land IS which is slightly concaved as denoted at C so that the cut will be square or with a straight bottom. Directly in rear of the land II, the tooth tapers gradually rearwardly as indicated at I'I, providing a flat surface, the sides of which converge as shown, thereby affording shouldered body portions I8 on opposite sides of the rear sloping wall I'I.

Beneath and flush with the pointed cutting edge I3 is a straight vertically disposed apical edge I3a, which inclines rearwardly and in radial direction, at an angle of the order of 15 as related to the radius of the body I0 intersecting the pointed cutting edge I3. Similarly straight, vertically disposed walls Ida and I5a incline rearwardly and in a radial direction at an angle. these walls extending directly from the respective cutting edges. The lower or inner edges of the walls I 4a and I5a merge or blend by outwardly inclined concave curvilinear surfaces Mb, I5b with the sloping rear wall I 'I of the tooth directly in advance, while the apical edge I3a concavely curves forwardly and thence merges into flat surface. 'I'hus the tooth bases are plow-like so as to feed the cut metal away to each side of the cutter. It is to be understood that the expressions "rearwardly and "advance as above used, are employed with respect to the direction of rotation of the cutter when in operation.

It will be observed that the milling cutter has the pointed cutting edges I3 of the teeth disposed midway of the transverse width or thickness of the peripheral surface so that the straight cutting edge portions I4 and I5 are of the same length.

In the operation of the cutter, it will be manifest that a dual peeling or shearing action by the straight cutting surfaces I4 and I5 achieves the desired result more elllciently with less load or stress on the teeth. Ordinarily, the weakest portion of the tooth of a milling cutter is the point. but in this instance, the pointed cutting edge I3 has the greatest or strongest backing, due ta 3 the sloping backing wall I1. This is found greatly to militate against tooth breakage. The curvilinear surface I8 enables cuttings to be readily discharged and prevents them pocketing or interfering with the work.

It is to be understood that numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as dened in the 8431181681 What 1 claim is:

A milling cutter comprising a metallic cylindrical body having an annular row of teeth on the peripheral surface thereof, each of said having an intermediate pointed cutting edge and straight rearwardly inclined oppositely vextended cutting edges tapering from said pointed edge rearwardly with respect to the direction of rotation of said body and each inclined cutting .edge terminating at a side edge of the respective tooth, said teeth having lands concave transversal;r of

4 the circumference rearward of the cutting edges and struck substantially on the arc of the circle. the radial surface of each tooth raking rearwardly relative to the direction of rotation and terminating in an outwardly inclined curved shallow concave pocket so as to form a plow-like base at the tooth front, and an integral backing for each tooth merging with the concave pockets of the next succeeding tooth.

mf HAGE.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 259MB Crane May 30, 1882 `1,529,917 Redinger Mar. 17, 1925 2,010,353 Edgar Aug. 6, 1935 2,183,982 Robbins Dec. 19, 1939 2,346,343 Aber Apr. 11, 1944 2,476,749 Marsh July 19, 1949 

